$green = #02a774;
$yellow = #F5A100;
$bc = #e4e4e4;

//根据像素比缩放1px像素边框
@media only screen and (-webkit-device-pixel-ratio: 2)
	.border-1px
		&::before
			transform scaleY(.5)

@media only screen and (-webkit-device-pixel-ratio: 3)
	.border-1px
		&::before
			transform scaleY(.333333)
			
//根据像素比来使用2x或3x图
bg-image($url)
	background-image: url($url + "@2x.png")
	@media (-webkit-min-device-pixel-ratio: 3),(min-device-pixel-ratio: 3)
		background-image: url($url + "@3x.png")
		
//浮动清除
clearFix()
	*zoom 1
	&::after
		content ''
		display block
		clear both